Piano sounding-board.



PATENT OFFICE.

WILLIAM H. KNIGHT, OF BOSTON, MASSACHUSETTS.

PIANO SOUNDING-BOARD.

Specification of Letters Patent.

Patented Dec. 17', 1907.

Application filed April 15. 1907- Serial No. 3684MB.

To all whom it may concern:

Be it known that 1, WILLIAM H. KNIGHT, a citizen of the United States,residing at Boston, in the county of Suffolk and State of Massachusetts,have invented a new and useful Improvement in Piano Soundi11gBoa1'ds, ofwhich the following is a specification.

It is well known among piano makers that a crowning sounding boardgreatly improves the tone of the instruments. And this invention relatesto the production of such boards and it consists in a combination with apiano sounding board of otherwise suitable construction, of bars or ribsattached thereto and of a frame to which the board is attached, allsubstantially as hereinafter described and pointed out in the claim. I

In the accompanying drawings, forming part of this specification, Figure1 is a rear elevation of an upright piano frame, showing generally thearrangement of the frame and the run of the sounding board and its barsor ribs relatively thereto and as to the board. Figs. 2 and 3 aresimilar views lengthwise of two of the bars or ribs, before beingattached to the board; Fig. 2 showing a bar of one thickness of wood andFig. 3 a bar of two thicknesses or layers glued together. Figs. 4 and 5are cross sections on dotted lines 4& and 5 5, Figs. 2 and 3,respectively. Fig. 6 is a vertical section on dotted line 6-6, Fig. 1.Fig. 7 is a horizontal section on dotted line 77, Fig. 1. Figs. 8 and 9are similar elevations of one of the end-posts or uprights of thepianoframe, Fig. 9 showing it in its most approved form for the purposes of this invention. Fig. 10 is a horizontal cross section on dottedline 1010, Fig. 9.

In the drawings, A represents the frame of an upright piano, B is thesounding board, and C, C are the wooden bars or ribs attached to oneside of the sounding board, all as well known except as to the featureshereinafter particularly described and which constitute this invention.

Each bar C is convexat and along one edge a and concave at and along itsother and opposite edge 6, and, in each instance, from end to end of thebar. This convexity and concavity of the bars substantially correspondwith each other, and in each instance it is secured by steaming the barand in that condition then bending it over a suitably shaped former, towhich it is confined until it has become set to the shape thereof, allas well known'in bending wood by the steaming process.

D, D are the opposite end-uprights of the piano frame, and each uprighthas a similar convex face E which extends the height of the upright andin each instance corresponds to the convexity of the bars O.

The several bars C of the sounding board A are relatively arranged as toeach other and to the several edges of the sounding board as well known,but with their convex edges a resting on or in contact with the boardand in this position they are severally glued or otherwise suitablyattached to the board as ordinarily practiced for the attachment of barsor ribs of the usual form to sounding boards, or otherwise suitably, andas the ribs or bars at and along their attaching edges a are convex theboard is thus brought to or given a crowning shape corre spondingsubstantially to the crown or convexity of the several bars. The boardA, prepared with its bars or ribs C all as described, is glued orotherwise suitably attached by the concave side of the board to theconvex faces E of the end-uprights D of the frame A; and thus not onlyis the sounding board of itself crowned as desired, but its retention insuch shape is insured because of its attachment as explained tosubstantially corresponding convex faces E of the frameuprights D.

Having thus described my invention what I claim and desire to secure byLetters Patent is,

The combination with a piano sounding board, of a series of wooden ribsor bars which severally, at and along one and the edge of each by whichit is secured to the board, are convex from end to end and at and alongthe other and opposite and unattached edge of each are substantiallycorrespondingly concave from end to end, and a piano frame havingopposite end-uprights,

each of which has a convex face which eX- my hand in the presence of twosubscribing tends in the direction of its height, and sub- Witnesses.stantiall corresponds to the convexity of said bal s, and has thesounding-board at- WILLIAM G 5 taclled thereto, all substantially asdescribed Witnesses:

and for the purposes specified. ALBERT W. BROWN, In Witness whereof, Ihave hereunto set MARION E. BROWN.

